This Recommendation provides a flexible mechanism for digital
subscriber line (DSL) transceivers to exchange capabilities and to select a
common mode of operation. It includes parameters relating to service and
application requirements as well as parameters pertinent to various DSL
transceivers. This Recommendation is currently an integral part of the
start-up procedure for ITU-T Recs G.991.2, G.992.1, G.992.2, G.992.3, G.992.4
and G.992.5. It is anticipated that future DSL Recommendations will also be
able to make use of this Recommendation. Provisions are also included for
exchanging non-standard information.